If you are amazed by this, youll be amazed to learn something about the horse:

They are also mammals and thus have almost all the same bones as we do!

Below what you would call their “Knee” is actually all the same bones as in our hand! They only have one “digit” (finger) and the hoof is pretty much a really tough fingernail! from the Knee down, they also have no muscles!!!!!

For a tangentially related anatomy quirk, bend any finger 90 degrees at the first knuckle, use your other hand to move the end of your finger up and down, and you should find that you have completely lost control of your fingertip.

Quick question; when I race my mountain bike on a longer descent (4> minutes) my hands begin to cramp and I feel it in my knuckles. Is that pain actually in my knuckles or is it my body misinterpreting what’s happening?

This is going to sound pretentious, so sorry, but I didn’t realize this wasn’t common knowledge. For instance, when your grip is failing from lifting something heavy, your fingers aren’t burning, your hand and your forearms are. Just make a fist and relax it and look at your forearm.